BigCommerce Customer Sync Aborts: "Customer record has already been synchronized with another Customer record with external ID"

Hi ​@prachodayabagade65:

When an order is created with guest customer, we do not create customer account with that order. We use guest customer account chosen in store settings as the customer in order.
I tried reproducing your scenario but I am not able to. For me, when the customer creates an account and then creates the order, we create the customer record and then create order.
Are you sure that there is other customer record with the same email preexisting in ERP?

Alternatively, you can also reach out to acumatica support and we can assist you with the investigation.  

Hi ​@tusharpandita74 ,

I confirmed that the email already exists in the ERP under our configured Generic Guest Customer Account. However, there is no corresponding record for that external ID in BCSyncStatus,

Do you know which validation the Commerce Connector uses to detect this duplicate if it isn't coming from BCSyncStatus?

​@prachodayabagade65 

From reviewing the code, it looks like the connector first searches for an existing ERP customer by email (using the customer's Default Contact email) before creating a new synchronization record. If it finds an existing customer with the same email, it treats it as a matching customer.
Based on this flow, the BCSyncStatus mapping would be handled after the customer matching step, so even if you don't see a BCSyncStatus record yet, the duplicate check can still occur first.

Could you please check whether this email exists on any customer's Default Contact in Acumatica? You can use the following SQL query:

SELECT
    B.AcctCD AS CustomerID,
    B.AcctName,
    C.EMail
FROM BAccount B
INNER JOIN Contact C
    ON B.DefContactID = C.ContactID
WHERE C.EMail = 'customer@email.com';

If this query returns a record, please verify whether it is the expected customer or the Generic Guest Customer.

Hope it helps!